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37 #define VIRTIO_BLK_F_BARRIER 0x0001 /* Does host support barriers? */
38 #define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */
39 #define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */
40 #define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */
41 #define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */
42 #define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/
43 #define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */
44 #define VIRTIO_BLK_F_WCE 0x0200 /* Writeback mode enabled after reset */
45 #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */
46 #define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */
48 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
50 struct virtio_blk_config {
51 /* The capacity (in 512-byte sectors). */
53 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
55 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
57 /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
58 struct virtio_blk_geometry {
64 /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
67 /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */
68 struct virtio_blk_topology {
69 uint8_t physical_block_exp;
70 uint8_t alignment_offset;
75 /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
83 * Usage is a bit tricky as some bits are used as flags and some are not.
86 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
87 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
88 * and may not be combined with any of the other flags.
91 /* These two define direction. */
92 #define VIRTIO_BLK_T_IN 0
93 #define VIRTIO_BLK_T_OUT 1
95 /* This bit says it's a scsi command, not an actual read or write. */
96 #define VIRTIO_BLK_T_SCSI_CMD 2
98 /* Cache flush command */
99 #define VIRTIO_BLK_T_FLUSH 4
101 /* Get device ID command */
102 #define VIRTIO_BLK_T_GET_ID 8
104 /* Barrier before this op. */
105 #define VIRTIO_BLK_T_BARRIER 0x80000000
107 /* ID string length */
108 #define VIRTIO_BLK_ID_BYTES 20
110 /* This is the first element of the read scatter-gather list. */
111 struct virtio_blk_outhdr {
116 /* Sector (ie. 512 byte offset) */
120 struct virtio_scsi_inhdr {
127 /* And this is the final byte of the write scatter-gather list. */
128 #define VIRTIO_BLK_S_OK 0
129 #define VIRTIO_BLK_S_IOERR 1
130 #define VIRTIO_BLK_S_UNSUPP 2
132 #endif /* _VIRTIO_BLK_H */